<?php
    add_action('admin_menu','hudp_setting_page');
    function hudp_setting_page(){
        add_theme_page('Theme option wordpress','HUDP option','manage_options','hudp_setting','hudp_setting_page_fn');
    }
    function hudp_setting_page_fn(){
        ?>
        <h2>This is theme option for hudptheme</h2>
        <?php
    }
?>